Return to flip book view

1.1 IB Psychology

Page 1

IB Psychology The Biological level of Analysis 1 1 Outline principles that define the biological level of analysis IB Psychology www PsychologyIB com IB PSYCHOLOGY THE BIOLOGICAL LEVEL OF ANALYSIS A model short answer question SAQ response to the examination question Outline principles that define the biological level of analysis Important This examination question commonly takes the form Outline two principles that define the biological level of analysis If you mention there are three principles and state each the examiner is required to award marks on the first two you have listed Thus if you list principles 1 2 and 3 in order in your introduction But go on to expand on principles 2 and 3 The examiner has to mark you on principles 1 which you have mentioned but not outlined and 2 And award no marks for principle 3 Yes very very pedantic 1 1 OUTLINE PRINCIPLES THAT DEFINE THE BIOLOGICAL LEVEL OF ANALYSIS Biological psychology is a branch or type of psychology that brings together biology and psychology to understand behaviour and thought Biological psychology looks at the link between biology and psychological events such as how information travels throughout our bodies neural impulses axons dendrites etc how different neurotransmitters effect behaviours There are three principles that define the biological level of analysis which will each be covered in turn Principle 1 There are biological correlates of behaviour This means that there are physiological origins of behaviour such as neurotransmitters hormones specialised brain areas and genes The biological level of analysis is based on reductionism which is the attempt to explain complex behaviour in terms of simple causes Principle 1 demonstrated in Newcomer et al 1999 performed an experiment on the role of the stress hormone cortisol on verbal declarative memory Group 1 high dose cortisol had tablets containing 160 mg of cortisol for four days Group 2 low dose cortisol had tablets with 40 mg of cortisol for four days Group 3 control had placebo tablets Participants listened to a prose paragraph and had to recall it as a test of verbal declarative memory This memory system is often negatively affected by the increased level of cortisol under long term stress The results showed that group 1 showed the worst performance on the memory test compared

Page 2

IB Psychology The Biological level of Analysis 1 1 Outline principles that define the biological level of analysis to group 2 and 3 The experiment shows that an increase in cortisol over a period has a negative effect on memory Principle 2 Animal research can provide insight into human behaviour This means that researchers use animals to study physiological processes because it is assumed that most biological processes in non human animals are the same as in humans One important reason for using animals is that there is a lot of research where humans cannot be used for ethical reasons Principle 2 demonstrated in Rosenzweig and Bennet 1972 performed an experiment to study the role of environmental factors on brain plasticity using rats as participants Group 1 was placed in an enriched environment with lots of toys Group 2 was placed in a deprived environment with no toys The rats spent 30 or 60 days in their respective environments before being killed The brains of the rats in group 1 showed a thicker layer of neurons in the cortex compared to the deprived group The study shows that the brain grows more neurons if stimulated Principle 3 Human behaviour is to some extent genetically based This means that behaviour can to some extent be explained by genetic inheritance although this is rarely the full explanation since genetic inheritance should be seen as genetic predisposition which can be affected by environmental factors Researchers interested in the genetic origin of behaviour often use twins so that they can compare one twin with the other on a variable such as intelligence depression or anorexia nervosa Identical twins monozygotic twins MZ are 100 genetically identical as they have developed from the same egg They therefore act as a control for each other Fraternal twins dizygotic twins DZ have developed from two different eggs They share around 50 of their genes so they are no more similar than siblings Twin research never shows a 100 concordance rate so it is believed that genes are a predisposing factor rather than the cause of behaviour Therefore it is also important to consider what environmental factors could influence the expression of the genetic predisposition Principle 3 demonstrated in Bouchard et al 1990 performed the Minnesota twin study a longitudinal study investigating the relative role of genes in IQ The participants were MZ reared apart MZA and MZ reared together MZT The researchers found that MZT had a concordance rate of IQ of 86 compared to MZA with a concordance rate of IQ of 76 This shows a link between genetic inheritance and intelligence but it does not rule out the role of the environment Source PsychologyIB com